| MENDEL'S LAW. |
By W. J. SPILLMAN,
U. S. DEPARTMENT OF AGRICULTURE.
NO discovery in recent years has aroused more interest amongst biologists than that of Mendel's Law. If subsequent investigations confirm it as those thus far made have done it can not be considered less than epoch-making. Its importance to plant breeders seems hardly less than that of the atomic theory to the science of chemistry. Professor Bateson, of Cambridge, says there is reason to believe that the plant breeder may eventually be able, by means of this law, to produce a desired hybrid type with the same degree of accuracy as the chemist now constructs a compound. It is impossible, on the threshold of such a discovery, to state just how far-reaching its importance is; we must wait for further investigation before hoping for too much.
As the history of this discovery is not yet generally known, it may be stated that Mendel's original paper was published in an obscure periodical at Brünn, Austria, in 1865.[1] This publication received slight notice until De Vries, in March, 1900,[2] published an exact counterpart of Mendel's theory, including some technical terms proposed by Mendel, and gave some of the results of his own researches to confirm the theory. Shortly after this, Correns of Germany and Bateson of England published results of their own work, showing that each of them had discovered the same law. Meanwhile the writer, working on hybrid wheats in this country, announced the law (but not the theory) in November, 1901.[3] The knowledge of this discovery has become general only during the past few months. It now remains for other investigators to apply it to their own results for confirmation or modification.
As the distinction between varieties and species can not always be drawn with exactness, and particularly since Mendel's law applies alike to crosses and hybrids, it seems justifiable, at least in a discussion such as the present one, to conform to the growing usage of biologists in this country by using the term hybrid to include crosses of all kinds, whether between varieties or distantly related species. I shall, therefore, use the term hybrid in this sense. In the following
